3.1 Sample information and demographics
From January 2021 through December 2023, a total of 19,680 pediatric inpatients diagnosed with ARTIs were admitted to Hainan Maternal and Child Health Hospital. The demographic details of the cases have been summarized in table 1. The age range of these patients spanned from 1 month to 18 years, with an average age of 2.97 ± 2.86 years. The gender distribution exhibited a notable skew towards males, constituting 12,126 (61.62%) of the patient cohort, while females accounted for 7,554 (38.38%) (Table 1).